Zirconium-oxide complex and method of producing and using the same



Patented Nov. 24, 1925.

umrso s'rA'r'ss OFFICE,

crmmiss xmzrn, or NIAGARA rams, new 1031:, nssxenon 'ro. rnn 'rlranro'mALLOY MANUFACTURING comramz, or NEW roux, n. Y., a CORPORATION or MAINE.V

'zIncomUM-oxmr: cournsx ENnrrn'rrron or rnonuome AND u smo- THE SAME.

I No Drawing.

To all whom it may concern-r Be it known that I, CHARLES J KINZIE, acitizen of the United States, and a resident of Niagara Falls, in thecounty of Niagara and State of New York, have invented a 7 novelzirconiumsoxide Complex and Method of Producing and Using the Same, ofwhich the following is a specification.

My present invention relates to the use of zirconium oxide, or that isto say zirconia,

as an opacifier in finally vitrified glass products, includingparticularly enamels, and its objects comprise provision of a. moreeconomically and readily workable process whereby from brude materials,or partially purified preparations, consisting principal- 1y ofzirconia, remaining impurities, discolorative of the final enamel may beeliminated or rendered comparatively impotent to prevent desiredwhiteness.

The increaslng importance of zirconia as an opacifier in lieu of tinoxide, antimony oxide, etc., 1n enamelling, has recently stimulatedinvention of various processes.

for more perfectly concentrating or separating it from such, forspme'purposes, undesirable, impurities, for example silicon, iron,titanium, etc.,'or their compounds, more or less of which respectivelyare usually found associated therewith as in the natural ores.

Such a process is that of Letters Patent No. 1,351,091, granted to LouisErBarton August 31st, 1920, whereby is produced, "as from ore, a productconsisting essentially of zirconium cyanonitride or carbide and which,on calcination, yields a comparative- 1y pure,but crude zirconia whichhowever generally useful as an opacifier, orfor other purposes,nevertheless usually retains so much still of the referred toin'ipurlties and of particles of carbon or its'compounds as to beprohibitive of such whiteness as may be desired in certain enamel waresbecause impartive of undesirable, for example distinctmill along withthe previously prepared purposes insufliciently purified preparationsare not infrequently found unsuitable be-' Application filed'April 10,1923. Serial no. 631,215. I

cause their said impurities can be only'partially or inadequatelydecomposed during the necessarily comparatively brief exposure thereof,and in a preponderance ofthe frit, to such temperatures asare"permissible in sistence of said particles in. substantially theiroriginal state istOo often so dull, gray, or rough, as not to satisfycertain commercial conventional requirements. It follows,

therefore, that such previous zirconia preparations are, unless furtherrefined at too ofmn prohibitive cost, unavailable in the manufacture oncommercial scales of white enamel ware by wet processes.

- I have discovered that if to such a relatively insufliciently purifiedor crude zirconia p refiaration therel be added, illildf' w e enamellmgoperations proper, alessquantity' of a mixture COIIlpIlSlIlg ma- Vanceof t terials such, and in such proportions, as if independentlyco-melted would yield a product designatableas a. vitrification, i. e,

a solidified glass or enamel (such a mixture being herein, as in theart, designated as a frit), and the thus composited charge besufficiently highly and protractedly heated, fiuxing, or other reactionsattributable to presence of said added frit will occur, such as to,effectively for' my purpose, so decompose the obectionable darkeningparticles,.or so induce transformation or transference of more or lessof their constituents into innocuous forms ,or novel complexes, orelimination'as by volatilization of' others, thatmy resulting thus, asit were, sintered or fritted zirconia complex will prove comparativelydevoid of enamel-darkening or otherwise injurious constituents such asto prohibit thereafter employment as an opaclher 1n white enamels.Furthermore, my thus intermediately prepared complex of the rela tivelycrude or insufiiciently purified. zirconia with ingredients of anindependently thereof glass-yielding frit seems to beneficiallyfacilitate assimilation, and homogeneityi of distribution, ofitszirconia durmgthe subsequent actual enamelling operations and also inthe resulting enamel. product thereby enhancing 1 and 'improving theopaqueing effects. l

' high temperatures of my employed mixture gredients well comminuted,or,

of comparatively crude zirconia-containing material; with a lessquantity of the unvitrified or fluid materials of a glass-yielding fritinvolves subjection, of the charge and particularly of the thereinimpurities to wigorous fluxlng reactions, the decomposing effects ofwhich seem attributable to conjoint action by the siliciousoFotheraoidforming *elements with alkali substances, such as sodium,potassium, etc., or with suitable bases, such as barium, calcium, etc.,both classes of which (preferably more of the acid) are contributed tomy charge by the addition thereto of such mixture of unvitrified moltenglass or frit constituents as may be indicated and employed in eachcase.

The following is an example of how my invention is workable and itscomplex opacifier product obtained.

The crude or insufficiently refined zirconia material, or preparation,is milled,

preferably to such fineness that 'all Will pass through. a 300 meshsieve To thisis then added a less indicated, composition or mixture ofingredients qualified When by itself co-melted and cooled to yield avitrified. glass, including enamel, product; r This addition isthoroughly mixed with the zirconia-containing material and may be madethereto in the form of a unmelted mixture of the glass-yieldinginpreferably, if so indicated, preliminarily melted to fluid glass,tapped, cooled, milled fine and so used.

The following is an example of ingredients and proportions suitable toconstitute the added mixture thereof in either its unmelted andcomminuted form or in its proliminarily melted and .then comminuted formas hereinbefore explained.-

Parts. Feldspar 100. Quartz 49. 20 Borax 39.80 Saltpeter r 16. Limestone.3, H Fluorspar Z 3. 36 Magnesite 2. 59 Cryolite 30.30

Satisfactory results are attainable from proportioning the charge so asto contain about 100 parts of the milled zirconia-containing material tosay about .10, or as I usually prefer 12, parts of the theretoaddedfrit.

The charge is then heated to a relatively high temperature preferablyabout 1050 C. for a relatively protracted period, say from one topreferably about three hours, or until the impurities appearsufficiently decomposed; it is then cooledymilled to quantity of anypreferred, or

previously dissolved during obtained by the practice of my-invention asper the above example thereof was approximately. as follows: 1

. 'er cent. Zirconium oxide (ZrO 83. 53 Silica (SiO 11.81 Soda (Na O)0.97 Calcium oxide (CaO) 0.54 Boron oxide (B O 0.51 Alumina (A1 0,) 1.O4: Magnesia (MgO 0.07 Potassium (K 0 0.37 Fluorine 1.16

It will be understood that successful prac tice of my invention is notrestricted to the use therein of exactly the above tabulated mixture ofglass-yielding ingredients, nor

to resulting zirconia-containing opacifiers of exactly the above statedcomposition.

Others also can be used, as I have indicated,

with equal or greater success, according to warying conditions, one oftheir common, and as I believe novel, and indispensable characteristicsbeing that in my said opacifier products the zirconia content is soaltogether predominant and their, if othgwise treated, glass-yieldingcontent s5 so much less as to completel distinguish them as regardscompositlon, orm, function and applicability from any hitherto knownproducts containing zircon-ia in association with glass-yieldingconstituents, my said products being of a fritte d or sintered ratherthan vitrified .consistency.

For further examples, I have, in the prac- 16 70 ticejof my invention,successfully used glassyielding Hits of the so-called high lead typefo'r'cast iron enamelling, also such frits of the high boron type.Besides-these I have used several others, such as those com monly knownas soda lime glass, potash dead crown glass, etc., but I prefer to use acomposition such as I have above tabulated because of its lowersintering or fritting pointand alsoon account of its freedom from suchsubstances as barium, lead or antimonycompounds, considered asobjectionable in enamels'for use in the culinary arts. t

It will also be understood that my invention can be more or lesssuccessfully praciced by aid of heat treatments otherlift) than thoseabove'specified, the latter being given merely as examples ofapproximately those usually p'referred, but which ma be more or lessvaried a smay be indicated in any particular instance, .to' thoseskilled in the art, so lon as thezirconia is so predominant and thetemperatures are so high and so protracted as toensure the'requireddecomposition of the impurities and which, as above intimated, could notbe expected from such heat or other treatments as approved inenamelling, and particularly in the white enamelling of cast or sheetiron articles.

To the vigorous fiuxing'actions above r ferred to may, I believe beattributed my resulting improvements in color, due, it

would-seem, frombreaking up of undesired more or less discolorativeimpurities'pres till ent,-such for instance as silicon, its carbide,\ferr'o-silicon, carbon, its compounds, etc, and their' transformationsinto less discolorative :forms, such, for example, ,as' silicon intosilica or other compounds, and also the elimination of, carbon as 'byvolat1lization, while my overcoming of'the'cream or yellow tonesattributed to iron .or its com pounds may be due to their recombinationswith other and whiter elements as for example contained in certain clayswhose content of iron may be as highas 1% and yet the clay, whencalcined, remains quite light in color. It seems probable that'some suchcombinations may be effected .by my said heating of my mixture of crudezirconiaf mate-rials with a less quantity of the independently thereofglass-yielding materials.-

Having now described my invention, what I claim as new and desire tosecure by Letlei-s Patent is the following, viz; v

' 1. The method of-treating material con from, cooling the resultingfrit, comminuting it, addingit as an op'acifier to an enamelyieldingfrit, heating the resulting charge, and'cooling-it.- H i 3. The methodof treating material composed preponderatin ly of zirconia, butcontaining also undesired impurities which comprises mixing saidmaterial with a rela tively small duantity of an unvitrified, in-.

dependently thereof, glass-yielding frit, and

'heating the resulting charge until said impurities shall havebeendecomposed and eliminated therefrom.

4. The method of'treating material coin posed prepondera-tingly ofzirconia, bu't con tainingalso undesired impurities which comprisesmixing said material with a relativelysm'all quantity of an unvitrified,independently thereof glassyielding frit, and

heating the resulting charge to above 10Q0 C. until said impuritiesshall have been elin1- inatedtherefrom. i

5; The method of treating material composed preponderatingly ofzirconia, but containing'also' undesired impurities which I comprisesmixing said material with a relatively small; quantity of anindependently thereof glass-yielding trit, and heating the charge duringmore, than. one hour until said impurities shall have been eliminatedtherefrom.

posed preponderatingly of zirconia, but containing also undesiredimpurities Which compr ses mixing said material With'it relatively smallquantity of an unvitrified, independently thereof glass-yielding frit,and heating the charge to above 1000 C. during more than one hour untilsaid impurities shall have been eliminated therefrom.

7. The method of treating material composed preponderatingly ofzirconia, but containing also undesired 'iinpurities which comprisesmixing saidmaterial with com minuted glass-yielding ingredients andheating the resulting charge until said impurie ties shall havebeenrdecomposed and eliminated therefrom. I

8. The method of treating material composed preponderatingly ofzirconia, but containing also undesired impurities which comprisesmixingsaid' material with a relatively small quantity of another mixturecomprising basic, and also acid-yielding constituents and heating thecharge containing. co-mixtui'e of both-s a'id mixtures until saidimpurities shall have been decomposed and eliminated therefrom.

t). The method ofttreating posed preponderatingly of zirconia, "butcontaining also findesired impurities which comprises mixing saidmaterial with a relatively small quantity ofanother mixture havingbasic, and illS0 'II101B'Of acid-yielding than basic, "constituents andheating the charge containing co-mixtur'eoi' both said -inixturesuntilsaid impurities shall have been decoinposedand eliminatedtherefrom.

10. The method of opaqueing' glass in- :cluding enamellwhich' com risesco-heating material 'coin-- 1 6. The method of treatin material coinarelatively" fusible unvitri ed glass or frit with a material composedpreponderatingly of zirconia but also containing undesired iao 'impurities; cooling and eomminuting the resulting sintered product,co-mixing said product with a greater quantity of a 'glassyieldingfrityand heating the co-mixture until said impurities are decomposed andeliminated therefrom and then cooling the charge to vitrificationthereof. I

11. The method of opaqueing glass including e'namel which comprisesco-melting a relatively small quantity of a relatively :l'usibleglass-yielding quantity of a material composed preponderatingly ofzirconia but also containing undesired impurities; cooling andcomminuting the resulting sintered product; ico-mixing a relativelysmall quantity-of said product with a greater quantity of an unvitrifiedglass or frit other thanthat first mentioned; and heating the co-mixtureuntil said impurities are decomposed and eliminated frit with agreatergled basic and acid-forming lngredients.

therefrom and then cooling the charge to quantity of independentlythereof glassyielding materials.

} 13. As a new article of manufacture an unvitrified opacifier mixturecomposed preponderatingly of zirconia' and comprising also a relativelySmall quantity of commin- 14. As a new article of manufacture anopacifier complex composed preponderatingly of a sintered mixture ofzirconia with a relatively small quantity of basic and acidformingingredients, the acid-forming being greater in quantity than the basic.

' CHARLES iL KINZIE.

